I've tried m-stak and it worked for me. I had great endurance, and recovery, strenght gain during workouts. I was the first supplement I ever tried besides creatine. Only bad thing was I had crazy insomnia and after I was off of it I felt tired/rundown.

I did the M Stak a while ago, when it came out. I noticed extreme pumps, but just for the last two workouts. I beleive this is just the methoxy that kicked in. As far as gains go, trying 2 bottles in a row could do something, but is too pricey IMO.

I've used both, stak 2 didn't do anything at all. The first week or so of M-stak I thought it was the greatest supplement ever. Then I stopped feeling the effects and realized that the stims and the massive placebo effect were the only things helping me. Then I did a little research and realized that the doses for pretty much every ingredient was insanely low. Maybe if you increased the dose (taking more then 1 pack) the stuff would work, but I DO NOT recommend that. Especially because their stuff is so expensive.

The animal products are all about marketing. The ads make it seem like they will make you this (well) animal in the gym and they are for intense lifters. Of course anybody that doesn't know better reads that thinks "well heck that's me, I'm intense and I want to be an animal".